| ⊦ perm(x, x + y) ↔ y = [] |
⊦ (∀ a. #oc(a, y) = 0) ↔ y = []
Used simplifier rules: perm: ⊦ perm(x, y) ↔ x ⊆m y ∧ y ⊆m x;%msubset: ⊦ x ⊆m y ↔ (∀ a. #oc(a, x) ≤ #oc(a, y));%ocappend: ⊦ #oc(a, x + y) = #oc(a, x) + #oc(a, y);% ⊦ m + n ≤ m ↔ n = 0; (s)%c: ⊦ m + n = n + m; from specification nat-basic%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic% ⊦ m ≤ m + n; (s)%a: ⊦ (x + y) + z = x + y + z; from specification list